1. Field of the Invention
This invention relates to a process for making a hair dyeing composition, to a hair dyeing composition and to a process of oxidative hair dyeing based on a dihydroxy-1,2,3,4-tetrahydro-naphthalene.
2. Description of the Prior Art
Oxidative dyes are important in the dyeing of hair. The color is generated by the products of the reaction of certain developers with certain coupling compounds in the presence of a suitable oxidizing agent.
Major developers include 1,4-diaminobenzene, 2,5-diaminotoluene, 3-methyl-4-aminophenol and p-aminophenol. Preferred coupling agents include alpha-naphthol, resorcinol, 4-chlororesorcinol, m-aminophenol, 5-amino-o-cresol and derivatives of m-phenylendiamine such as m-toluylendiamine and 2,4-diaminoanisol. These derivatives as well as the m-phenylendiamine itself have achieved importance as so called blue couplers based on their capability in generating blue hues by coupling oxidatively with 1,4-diaminobenzene and 1,4-diaminobenzene derivatives, respectively.
Several requirements are imposed on oxidation dyes suitable for dyeing of human hair. Such dyes have to be toxologically and dermatologically safe and they have to be capable of generating colorations of desired intensity. It is also important that a broad range of different hues can be generated by combining suitable developer and coupling components. Furthermore the obtainable hair colorations have to be fast to light, to permanent waves, to acid exposure and to rubbing. In any case, however, such hair colorations have to remain stable for at least about 4 to 6 weeks in the absence of light, of chemical agents and of rubbing.
The conventional blue couplers presently employed in hear dyeing compositions such as m-phenylenediamine, its derivatives m-toluylenediamine and 2,4-diaminoanisol as well as the more recently recommended blue couplers such as for example 1-hydroxy-3-amino-6-chlorobenzene and 2,4-diaminophenoxyethanol, are not capable of satisfactorily meeting the above mentioned requirements.